The
End of the Journey, Lake Ontario!

Lake
Guardian was nervous as she left Lake Erie, for she thought
that she might take a wrong turn and go over Niagara Falls! She was big
and strong, but no boat could survive a ride like that. She was relieved
to find the Welland Canal and make here way to beautiful Lake Ontario.
She had heard so much about the falls, and the breathtaking Thousand Islands
on the east end.

Lake
Guardian got out her map to trace her journey. She was very
interested in looking at how all the water in the Lakes eventually comes
through Lake Ontario because it is the last Lake before that water heads
out the St. Lawrence River and into the ocean. This means that a lot of
the dissolved substances and pollution she studied in the other Great
Lakes also has journeyed to Lake Ontario, which is one of the reasons
why Lake Ontario is the most polluted of all the Great Lakes. Lake
Guardian knew that another reason was its small size. It doesn't
have as much water to spread out the pollution.

Lake
Guardian traveled first by Hamilton and Toronto, Canada, passing
lots of big industrial factories and buildings. She remembered all the
factories and big machines she had seen along the shores of all the other
Great Lakes. Lake Guardian
was concerned about more than the smokestacks and air pollution she had
learned about. She was worried about chemicals dumped by the factories
and businesses into the water. Lake
Guardian thought about Herring Gull's friends the cormorants,
and what she learned in Lake Michigan about the chemicals from farms running
off into the water and settling to the bottom for small creature to eat.
She knew that this was happening with he chemicals from factories and
businesses too.

She asked Dave, the environmental
scientist, if there were other effects from these chemicals on the Great
Lakes besides polluting sediments and entering the food chain. Dave described
how some chemicals, such as nitrogen and potassium, from industry, farms,
and city areas are like food to green plants in the water, including algae.
"The algae grow very gig very fast, and we call it an algae bloom.
It eventually dies," Dave explained, "but when it does, the
bacteria that feeds on the dead algae takes a lot of the water's oxygen.
The more algae that blooms and dies, the more bacteria there is taking
oxygen from the water." Lake
Guardian knew that without oxygen, many species of fish could
not live. Dave explained that when a lake's oxygen levels are lowered,
some species die out--mayflies included-and others like sludge worms and
carp, that can tolerate low levels of oxygen move in. That's why scientist
look for changes in the kinds of animals living in the Great Lakes. It
tells them if too many chemicals are changing oxygen levels and upsetting
the balance of animals and nature, called the ecosystem.

Lake
Guardian got to work and collected samples and looked for algae
blooms all along the shoreline of Lake Ontario. She examined the different
species to see if she could tell if chemicals were changing the water's
oxygen levels too much.

By the end of the journey, Lake
Guardian had learned a lot about the beautiful Great Lakes.
She wanted to tell everyone about all that she had learned. What could
people do to help the Great Lakes? She was concerned about the many pollution
problems that she saw, but she know that things could get better. Lake
Guardian knew that by helping to collect samples and learning
more about the Lakes, she was part of the solution. That made her feel
proud as she journeyed up the St. Lawrence River to peek at the ocean
before heading back home.